Syringe device for supplying repeatable sample volumes



Oct. 14, 1958 M. s. REYNOLDS 2,855,928

SYRINGE DEVICE FOR SUPPIQ-YING REPEATABLE SAMPLE VOLUMES Filed July 12,1957 2- Sheets-Sheet 1 5% fim/emal ffzmzzz/rg 5/1 6 Q 51 Oct. 14, 1958M. s. REYNOLDS 2,855,928

SYRINGE DEVICE FOR SUPPLYING REPEATABLE SAMPLE VOLUMES Filed July 12,1957 v 2 Sheets-Sheet 2 I z I I I t A, E V 1 7. ,4. A I

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United States atent O 2,8559% SYRINGE DEVTCE FOR sUPi LYiNii REPEATABLESAMPLE VOLUMES Manning S. Reynolds, Chicago, Ill., assignor to CentralScientific Co., a corporation of Illinois Application July 12, 1957,Serial No. 671,634

3 Claims. (Cl. 128-218) My invention relates to a method and device forobtaming and supplying repeatable sample fluid volumes, and moreparticularly, to a method and device for repeat- .ably injecting testvolumes of fluid into a testing area or .space.

The need frequently arises in scientific work for repeatedly testingsubstantially identical volumes of gases or liquids. The volumesrequired may be different for dif- :ferent experiments, but for anyparticular experiment, it is desirable to repeatedly providesubstantially equal volumes of a gas or liquid.

A principal object of my invention is to provide a syr- Iinge device andmethod that conveniently supplies re- ;peated volumes of fluid.

A further object of my invention is to provide a syr-' tinge instrumentset which makes it possible for the experimenter to supply repeatedvolumes of a test fluid, and yet which permits him to supply the volumedesired fora gparticular series of tests.

Another object of the invention is to provide .a repeat-' :able volumesyringe device which is composed offew :and simple parts, which iseconomical of manufacture, convenient in use, and readily adapted to awide variety of applications.

Other objects, uses, and advantages will be obvious or become apparentfrom .a consideration of the following detailed description and theaccompanying application drawings.

In the drawings:

Figure l is a side elevational view of one embodiment of my invention;

Figure 2 is an exploded perspective view of the elements making up theembodiment of the invention shown in Figure 1;

Figure 3 is a longitudinal cross-sectional view through the device ofFigure 1, illustrating the manner in which ;the syringe is initiallycharged;

Figure 4 is a view similar to that of Figure 3, but illustrating aslightly modified arrangement;

Figure 4a is a fragmental elevational view illustrating ;a furthermodified arrangement;

Figure 5 is a view similar to that of Figure 3, but .illustrating anintermediate step in the operation of the device for providing thedesired volume of fluid that is to be repeatedly injected by thesyringe;

Figure 6 is a view similar to that of Figure 5, illustrating the syringepositioned to inject the desired volume of fluid that is to be repeated;

Figure 7 is a view similar to that of Figure 6 but illustrating thesyringe after the desired volume has been injected;

Figure 8 is an enlarged cross-sectional view along line 88 of Figure 5;

Figure 9 is a perspective view of a set of spacers or repeatable volumeproviding elements that accompany and form a part of my syringe device;and

Figure 10 is a diagrammatic plan view illustrating an other embodimentof my invention.

"ice,

Reference numeral 10 of Figure 1 generally indicates a mechanicalcontrol type syringe device, or syringe type device, in which theprinciples of my invention have been incorporated, while referencenumeral 10a of Figure 10 generally indicates an electrical control typesyringe device. The device 10 comprises a transparent (though it neednot be transparent) tubular cylinder 12 of a conventional syringe shapeincluding an enlarged portion 14 and a reduced portion 16, the latterreceiving a conventional tubular needle 18 or other fluid conduit meansas may seem desirable or necessary under the circumstances. The cylinder12 may be formed of glass or any appropriate material and includes acylindrical chamher 2%) terminating at an opening 22 at one end thereofand a passageway 24 at the other end thereof that leads to the tubularneedle 18. The cylinder 12 is formed with a collar 26 against whichcooperate (in the embodiment of Figures 1-4 and 59) a selectable spacer28, a permarientcylindrical spacer element 30, and annular knob orhandle 32 of syringe piston 34. Piston 34 of the. embodiments of Figures1-9 includes an elongate rod like element 36 which is integrally unitedwith a stop means in the form of handle or knob 32. Element 36 servesthe function of both a piston and a piston rod, it integrally unitingpiston portion 35 and piston rod portion 37. The element 36 is receivedin chamber 20 and may be sufiiciently long in length to substantiallyfill the available space in chamber 20 when only spacer 30 separateshandle 32 from contact with collar 26. The diameter of the element 36 isproportioned so that it will snugly but slidably fit within chamber 20to provide the sealing action required in devices of this type.

. The permanent cylindrical spacer element 30 is an annular memberformed from any appropriate substance and is provided with centrallydisposed cylindrical perforation 40 which receives the element 36. Thespacer 30 is formed with an annular groove or recess 42't0 receivethespring arms 44 of spacer 28. In the alternate arangement shown inFigure 4a, spacer 30a is made an integral part of piston 34a, handle 32ain effect being enlarged axially of the piston and formed with groove orrecess 42 to receive arms 44 of spacer 28.

Spacer 28 comprises a member having a predetermined thickness, andwhich, in the illustrated embodiment, is,

generally quadrilateral in configuration and is formed with a Ushapedslot 48 which receives the member 36. Spring arms 44 are integrallyunited into a resilient spring 45 formed from any type of spring metal.Spring 45 includes a looped portion 47 that is secured about stem 50 ofappropriate pin 52 which is tightly fixed in hole 49 of the spacer 28and binds the spring 45 against pivotal movement. The sides 54 of thespacer 28 may be knurled as at 56 for ease in handling same.

' As' indicated in Figure 9, I prefer to provide a set of spacers foreach syringe device 10. Each spacer 28a, 28b, 28c, 28d, and 28e isidentical to the spacer 28 except that the thickness is different. Theparticular spacer. se-

28 selected to provide a desired volume of fluid are received over themember 36 in the manner indicated in Figures 1 and 3. The spring arms 44of the spacer 28 are received in the annular, groove or slot 42 of themember 30 with the surface 60 of the member 28 abutting the end 62 ofthe spacer 30. This holds the spacer 28 to the spacer30.

the left as far as it will. go with. thespacers 28 and 30 interposedbetween handle 32 and collar 26 (the position of Figure 1) and then theneedle 18 placed in a source or container of thefluid that: isto hetested. The piston 34 is then at leastpartially withdraw-n. frorn 'tthecylinder (see Figure 3 which draws the fluidlinto the chamber 20 of thesyringe through passageway 24. At this point, it is immaterial whether'or not the spacers move with the piston. After a charge has been broughtinto the chamber 20, the air is expelled (if a liquid is employed) andthe piston 34 is moved to the left. of Figure 5 to expell. excess fluid,until the spacersprohibit further movement in this direction. Thispositions the syringe for discharge of the desired volume of fluid thatis to be repeatedly provided.

The spacer 28 is then gripped in the manner indicated in Figure 5, or bygrasping the knurled portions 56 of edges 54, and the spacer 28withdrawn as indicated in Figure 6. The piston 34 is then forced to theleft of Figure 6 to the position of Figure 7 which effects the dischargeof the desired volume of fi-nid by bringing spacer 30 into contact withcollar 26 (see Figure '7).

The c'olla r'26 and spacer 28 thus form spaced stop mernbers along thepath of operation of piston 34.

For each test of the fluid required, the foregoing steps are repeated.This insures that the same volume of fluid is provided for each occasionthat it is required.

The arrangement of Figure 4 is the same as that of Figure 3 except thatthe spacers 28 and 30 are in reversed positions. The embodiment of"Figure 4 operates in the manner described above, however, as does theembodiment of Figure 44.

Cylinder 12 may be provided with appropriate indicia as indicated inFigure 1'.

The device 10a' of Figure 10 includes a cylinder 12a that may beidentical to the cylinder 12 of Figure 1,; and

thus includes an enlarged portion 14a in which chamber a is formed and areduced portion 16a-in which pas sageway 24a is formed that lead to aneedle or some receiver for the repeatable volume to be supplied bydevice 10a. Cylinder 12a is preferably fixedly mounted in any suitablemanner, as by an appropriate clamp or the like. A piston 34a isreciprocably mounted in chamber 20, and includes piston portion 35a andston ro po t o -3. ha i es in flange 2 Flange 26a includes an extensionor arm 70 which op-, crates between two spaced limit switches 72 and 74of any appropriate type. In the embodiment illustrated, each switch isshown as including a switch arm 76 pivoted as at 7 8 and biased in thedirection ofthe arrow by compression springs 80. The switch arms 76 areelectrically connected by lead 82; they respectively engage contacts 84and 86 under the action of springs 80. Contact 84 is electricallyconnected to an appropriate source of electrical energy by lead 88 whilecontact 86 is connected to the stator coil 90 of appropriate shaded polemotor 92 by lead 93. The coil 9t) is connected to the source ofelectrical energy by lead 94.

Motor 92 includes a shaft 96 that moves crank arm 98 to reciprocatepiston 34a through link I00 and rod extension 101. Appropriate rollers102, may be provided for guiding the reciprocating action ofrod'extension 101.

A push button switch 104 of any appropriate type is connected betweenleads 88 and 93. Motor 92 includes, pole coil 106 that is connected tocontacts 108, '110, and 112 by appropriate leads. A switch arm 120 ispivotally connected to contact 110 for making contact: either contact108 or 112, depending on the direction of motor rotation that isdesired. Since shaded pole m otors' are; well known in the art, nofurther description of motor 92, is believed necessary, though it willbe assumed that motor 92 will move piston 344 upwardly of Figure fit)when arm 120 closes contacts 108 and 1 0,, idthat movement in theopposite direction is achieved by arm 120 closing contacts 110 and 112.In any event, the

showing of Figure 10 is for illustrative purposes only, and it is to beunderstood that any electrical arrangement which will reverse theoperation of piston 34a on contact of the extension or arm 70 with oneof the switches 72 or 74 would be satisfactory and is within the scopeof the invention.

In operation; assuming that. the extension or arm 70 is at the end ofits injection stroke (its uppermost position), the passageway 24a isplaced in communication with a supply of the fluidthat. is to beinjected, arm 120 is placed in contact with contact 112, and switch 104is closed to actuate motor 92. starts movement of piston 34a downwardlyof Figure 10, which draws fluid into the cylinder 12a and also closesswitch 72, which permits continued piston movement after switch 104 isreleased. When extension or arm 70 contacts switch arm 76 of switch 74-,switch 74 is opened which stops this downward or charging motion ofpiston 34a. Arm is then moved to close contacts 108 and 110, thepassageway 24a-p1aced in communication with the space into which therepeated volume is to be injected, and switch. 104 again closed, whichstarts the ejection stroke of the piston 34a that provides the volume offluid desired. Contact of the arm or extension 70 with arm 76 of switch72 terminates the injection stroke, the above steps being repeated foreach volume of fluid desired. Switch arms 76 thus form spaced stopmembers'along the path of operation of piston 34a.

The spacing between arms 76 of switches 72 and 74 determines the volumeof fluid that is to be repeatedly injected, and it is understood thatswitches 72 and 74 will in practice be mounted for adjustment of thespacingbetween them, though this is omitted in the showing of Figure 1'0for simplicity of illustration.

While the cylinder 12a is shown vertically disposed in Figure 10, itwill be appreciated that this showing is forillust rative purposes only,and that the syringe cylinder is capable of being used in a variety ofpositions.

An important advantage of my invention is that the piston and itsrepeatable volume defining means may be employed with a wide variety ofsyringes of the same nominal size. Since the piston diameters ofdifferent syringe cylinders may vary slightly for syringes of the samenominal size, it is apparent that changing syringes may change thevolume of the sample that is delivered.

However, this is entirely acceptable, as the goal is repeatable volumes,not exact volumes. The goal of repeatable volumes is attained so long asthe same syringe is used throughout a series of tests.

Both liquids and gases can be supplied by devices 10 and 10a with equalfacility.

The spacers 28 may be designed to provide liquid volumes on the orderof, for instance, .005 cc. up to .060 cc.; if the spacers are to beemployed to provide gas samples, a'larger volume range may be selected.

The foregoing description and the drawings are given merely to explainand illustrate my invention and the manner in which it may he performed,and the invention is not to be limited thereto except in so far as the,appended claims are so limited since those skilled in the art who havemy disclosure before them will be able to make modifications andvariations therein without departing from the scope of the invention.

I claim:

'1'. A repeatable volume syringe comprising a cylinderformed with afluid passageway at one end thereof permitting flow of fluid into andout of the cylinder, a piston forming rod like element reciprocablymounted in said cylinder and extending outwardly of the other end ofsaid cylinder, a handle carried by said element at its, outwardlyextending end, said handle limiting the movement of said element towardsaid passageway by engagement with said other end of said cylinder, aspacer of predetermined thickness removably mounted on said elementbetween said handle and said other end of said cylinder, and a spacerretaining member carried by said element between said handle and saidother end of said cylinder, said spacer carrying a pair of resilientarms that grasp said member to retain said spacer on said element,whereby, said cylinder may be supplied with fluid by withdrawing saidelement away from said passageway to draw fluid into the cylinderthrough said passageway and then said fluid ejected to the limitpermitted by said spacer, said member and said handle, by forcing saidelement toward said passageway until said spacer and said member ceasemovement by contact with said other end of said cylinder, whereupon saidspacer may be removed to permit ejection of a predetermined volume ofsaid fluid from said cylinder through said passageway based on thethickness of said spacer.

2. In a syringe device including a cylinder and a piston reciprocablymounted in the cylinder, the improvement wherein a pair of spaced stopmembers are provided along the path of operation of the piston whichdefine the piston stroke length required to provide a predeterminedvolume of fluid ejection from the cylinder, and means for repeatablyreciprocating said piston over said stroke length to draw saidpredetermined volume of fluid into said cylinder and eject saidpredetermined volume of fluid therefrom, said spaced stop memberscomprising a flange that is fixed with respect to said piston and a stopabutment that is fixed with respect to the cylinder, and a spacerelement removably carried by said piston and disposed between saidflange and said abutment, said spacer element defining said pistonstroke length, and being removed to eject said predetermined volume offluid from the syringe.

3. In a syringe device including a cylinder and a piston reciprocablymounted in the cylinder, the improvement wherein a pair of spaced stopmembers are provided along the path of operation of the piston whichdefine the piston stroke length required to provide a predeterminedvolume of fluid ejection from the cylinder, and power means forrepeatably reciprocating said piston over said stroke length to drawsaid predetermined volume of fluid into said cylinder and eject saidpredetermined volume of fluid therefrom, said spaced stop memberscomprising electrical switch means connected in an electrical circuitthat controls said power means, and arm means carried by said piston formovement between said switch means, and means for reversing thedirection of operation of said power means on contact of said arm meanswith one of said switch means.

References Cited in the file of this patent UNITED STATES PATENTS1,649,022 Eisele Nov. 15, 1927 2,216,354 Pletcher Oct. 1, 1940 2,602,446Glass July 8, 1952 2,607,343 Sarver Aug. 19, 1952

